Q: Unstable Wi-Fi with Time Capsule + Express Booster

Let's get to the next step and that is to configure the TC8350C and the TC into a roaming type network. Start by keeping both the TC & Express powered-off. (Note: We will get to the Express as the last "step" and concentrate on just the other two devices.)

 

• Perform a "factory default" reset on the TC. After it has completed, power it down.
• Now connect an Ethernet cable between one of the Ethernet ports on the TC8350C to the WAN (circle of dots) port on the TC.
• Power-up the TC. Give it about 5 mins to initialize.
• Run the AirPort Utility on your Mac or iPhone.
• Select the TC, and then, select Edit.
• Go to the Network tab. Change Router Mode to: Off (Bridge Mode)
• Go to the Wireless tab. Verify or change the value for Network Mode to: Create a wireless network.
• Enter the wireless network name you noted above in the Wireless Network Name field.
• In the Wireless Security field, select "WPA/WPA2 Personal."
• In both the Wireless Password & Verify Password fields, enter the wireless security password from above.
• Click on Update, and allow the TC to restart.

Just a note here to mention that when the TC has been reset back to factory default settings.......it will not appear in AirPort Utility, so it is not possible to Select, Edit, etc and perform that steps that are listed above at this time.

Instead, the setup "wizard" must be run to provide basic settings to the TC.

The setup wizard can be initiated by opening AirPort Utility and then clicking on the Other WiFi Devices button, then clicking on Time Capsule.

That will get the setup wizard up and running. It will suggest the correct setup in a window that looks something like the screenshot below, except that you will see the Time Capsule pictured, instead of the AirPort Express in the illustration.

For Network Name........Type in the exact same name as the Comcast wireless

For Base Station......Type in the same that you used for the Time Capsule before

For Password........Type in the exact same password that the Comcast wireless is using

For Verify.......Type in the same password again to confirm

Click the Next button in the lower right corner

The setup "wizard" will automatically configure the TC in Bridge Mode, so you do not have to worry about this.  The "wizard" will use the WPA2 Personal wireless security setting, so if WPA/WPA2 Personal is required to match the Comcast modem/router......then you can go back in using AirPort Utility and adjust the security setting that way if needed.

will the factory reset erase the backup file on my TC

No, only the network settings of the TC are erased during a factory default reset. 

The data on the TC hard drive is not affected in any way......since you would have to perform a completely separate and deliberate "Erase Disk" procedure to wipe the TC hard drive clean.

I'm going to let Tesserax take it from here, since he answered your post initially.

I did the factory reset twice and both times the TC showed up in my AirPort Utility.

Fortunately, you did not really reset the TC back to factory defaults.........because if you did......it would not show up in AirPort Utility at all unless you clicked on the Other WiFi Devices tab.

Since the TC was not really reset, it did show up in AirPort Utility using its previous settings, so you were able to simply Edit the settings as Tesserax instructed.

The one thing that is different about the setup of TC is the wi-fi network name is now the same as the Wi-Fi coming off the TC8350C (before there were two different network names).  Is this correct?

Yes it is, according to the previous discussion that you had with Tesserax  about a "roaming network".

Glad that things are working again.

1.  AirPort Utility takes forever to find TC.  It says 'no configured AirPort base stations" and thinks for a long time.  Eventually it connects.  That said, the 'Other Wi-Fi Devices' button doesn't have any options for me to reset.  I'm assuming this has something to do with my attempt to reset to factory settings.

At least two things have to happen in order for the AirPort Utility to "find" a base station:

1. The device hosting the utility must be connected to the same network that the base station is on via either a wired or wireless connection.
2. IPv6 should be enabled on the local network. This is enabled by default on both the AirPort base stations and Macs. Most other PCs have this featured enabled as well.
3. Not actually required, but the utility will also use the Bonjour protocol to help it "find" the base station.

Typically when you get the "no configured AirPort base stations" status message, it could one or more of the above items that would be the cause. In this case, you should still be able to access the base station by using the utility's File > Configure Other... menu option ... and yes, this could be the result of performing a factory reset.

2.  How do I get the Express online?

Ok, I as assuming that you now have both your TC8350C & TC working together properly and you now want to add the AirPort Express base station to the same roaming network ... correct?

If so, then again, you will want to perform a factory default reset on the Express. However, I would recommend that we use Bob's suggestion on how to set up the Express instead of manually configuring it.